It looks like several companies are learning what happens when you mess with the internet - and they're learning it the hard way. Several major companies have been hit by the collective powers of Anonymous after 4chan launched several distributed denial-of-service attacks. What many have been predicting for a long time now has finally happened: an actual war between the powers that be on one side, and the internet on the other. Update: PayPal has admitted their WikiLeaks snub came after pressure from the US government, and Datacell, which takes care of payments to Wikileaks, is threatening to sue MasterCard over Wikileaks' account suspension. Update II: Visa.com is down due to the attack. Update III: PayPal has caved under the pressure, and will release the funds in the WikiLeaks account.

Paypal.com is up and running as I write this.
Paypal has policies on whom they will do business with. Paypal is a US company; in the US, you are allowed to refuse to do business with anyone you want to, as long as those reasons have nothing to do with discrimination against a "protected class" (for example, you can't refuse to do business with someone because of their race, ethnicity, gender, etc). "Leakers" is not a protected class. Paypal is under no obligation to do business with Assange or his operation. Those attacking the Paypal site are criminals.